Multiphase lubricating system



Nov. 4, 1941. A. H. BATCHELDER 2,261,577

MULTIPHASE LUBRICATING SYSTEM W Filed April 17, 1939 2 Sheets-Sheet 1 00o 0 0 0 0 000 o 0 80 00 O o o INVENTOR ATTORNEYS 1941- A. H. BATCHELDERI 2,261,577

MULTIPHASE LUBRICATING SYSTEM Filed April 17, 1939 v 2 Sheets-Shet 24/1/20 0/4 +5 POLYMER 30 g LARD 0/4 +2 POLY/V R Q E MR 0/4 YMER 7 8 u Ig 200 220 240- 260 250 300 320 72*m 0e/"0/ure "F.

fiugus/l/s flba/cfie/aer INVENTOR ATTORNEYS Patented Nov. 4, 1941MULTIPHASE LUBRICATING SYSTEM Augustus H. Batchelder, Berkeley, Califassignor to Standard Oil Company of California, San Francisco, Calif.,acorporation of Delaware Application April 17, 1939, Serial No. 268,312

16 Claims.

This invention relates to a multiphase lubricating system, and moreparticularly to a lubricating system or composition comprising alubricating oil phase and one or more additional phases.

An object of the invention is to provide a useful lubricating system orcomposition having certain novel characteristics.

A further object is to provide a lubricating medium having a negligibleViscosity-temperature coeflicient over temperature ranges in the orderof at least approximately 50 F. and as great as 100 F. or more.

An additional object of the invention is to provide a lubricatingcomposition which will show substantially no loss of viscosity when thetemperature thereof is raised from approximately 200 to approximately300 F.

Another object comprises the production of a novel type of multiphaselubricating composition,

an oil phase and a continuous phase other than said oil phase containinga high molecular weight organic resinous material dispersed therein.

A still further object of the invention is the provision of a novelmethod for maintaining the viscosity of a lubricant substantiallyconstant over relatively wide temperature ranges.

It is also an object of the invention to furnish an apparatus suitablefor effecting lubrication with the multiphase system'here disclosed andfor carrying out the process of the invention.

Additional objects will be apparent from the detailed description of theinvention hereinafter iven.

Lubricating compositions containing viscous materials have been proposedheretofore; for example, viscous materials have been dissolved inlubricating oils in order to enhance the viscosity index of theresultingsolution (the term viscosity index is defined by Dean and Davisin Chemical & Metallurgical Engineering, vol. 36, pp. 618-619) Insuch'prior known compositions the viscous material has been in solutionin the oiland separation of the addition agent as an independent phasehas been carefully avoided as undesirable. The increase in viscosityindex of these types of solutions was effected by initially imparting tothe oil a large increase in viscosity at normal atmospherictemperatures, which increase resulted in a flattening of theviscositytemperature curve. This initial increase in viscosityrepresented the total increase to be obtained and was not latermultiplied or increased at elevated temperatures.

Although such an expedient has given some imoils, it has not beenpossible with these solutions to produce compositions having constantviscosities o-ver substantial temperature ranges such as 50 or 100 F.Further, the large initial increase in viscosity obtained by solution ofthe viscous material in the oil at ordinary atmospheric temperatures, insome instances necessitates the use of a lighter oil as the base stockfor the lubricant in order to avoid an unduly high viscosity at lowertemperatures and to meet the viscosity specifications for a given gradeof oil. This lighter base oil is consequently more volatile than heavieroils which would be used except for the presence of the addition agent,and such increased volatility tends to cause greater oil consumption andmay largely offset advantages presumed to result from the higherviscosity index.

I am also aware that variousinsoluble mate rials have been dispersed inlubricating oils to enhance the lubricating action thereof; forinstance, materials such as graphite, extreme pressure addition agentslike lead sulfide, and drying oil polymers which remain insoluble in theparticular base oil used even at elevated temperatures, have beenproposed. These'materials, by reason of their insolubility in the oil,have reduced the viscosity-temperature coefficient pf the lubricatingoil only to a minor or unappreciated degree, if at all.

It willbe noted that the above described prior art compositions arecharacterized by a dispersed material which is either entirely solublein the oil at ordinary temperatures, such as to F., or which issubstantially entirely insoluble in the lubricating oil not only atthese temperatures but also at elevated temperatures, such as from 200to 300 F. The. present invention is concerned with a different type oflubricating composition or system and is not to be confused therewith.

- I have discovered that lubricating compositions having negligibleviscosity-temperature coefiicients (viscosity-temperature coefficient isthe .slope of the viscosity-temperature,curve)i. e.,

negligible change of viscosity with change of temperature-may beobtained by utilizing a multiphase system.

According to the invention a first phase comprises a lubricating oil, asecond phase comprises a high molecular weight organic resinous materialand the two phases have certain solubility relationships. Thephases'comprising the components of my invention may be separately newor old, since it 'is the novel combination of commnnhi'c mink T vno'nvflac the nrima'rv feature of my invention rather than the composition ofthe independent components.

The lubricating oil phase of my composition may comprise a minerallubricating oil; a vegetable or animal oil; or a synthetic lubricantsuch as liquid, olefine polymers; hydrogenated, liquid olefine polymers;or other synthetic hydrocarbons having a viscosity in the range normallyutilized as lubricating oils. The second phase of my compositioncontains a high molecular weight resinous material which is highlyviscous and preferably one characterized by long molecules such as areobtained by chain reactions of the polymerization or condensation type.

Although there are a number of types ofmultiphase systems which may beutilized to accomplish the objects of this invention, one commonproperty of the systems which characterizes the invention is theprovision of a separate phase which tends to dissolve into thelubricating oil at high temperatures, such as 200 to 300 -F., and whichis substantially insoluble in the oil, and hence goes out of solution atordinary temperatures, such as 65 to 100 F. This second phase may besaid to be temperature-sensitive in that it tends to dissolve ordisappear at high temperatures and precipitate or reappear at lowtemperatures.

Various of the different types of multiphase systems are illustrated inthe drawings in which:

Figure I is a diagrammatic illustration of a two-phase system and anapparatus for contacting the phases to maintain them substantially inequilibrium.

Figure II represents a diagrammatic magnified view of a composition inwhich particles of the phase containing'organic resinous material aredispersed in the oil phase. The dispersed particles represented are ofgreater than colloidal size.

Figure lIIdiagrammatically illustrates a multiphase system and anapparatus for maintaining equilibrium between the several phases.

Figure IV represents a two-phase system in which one phase may be acolloidal solution or suspension in a dispersing medium other than thelubricating oil.

Figure V shows a diagrammatic and magnified view-of a colloidal phasedispersed in an oil phase and in which the dispersing medium for thecolloidal phase comprises particles of greater than colloidal size.

Figure VI gives curves showing the viscositytemperature characteristicsof compositions utilizing the present invention.

As described hereinabove, one phase comprises a lubricating oil whichmay be an oil of various types, e. g., mineral oil, vegetable or animaloils, and the synthetic hydrocarbons. The second phase of the multiphasesystem of this invention may be one of several difierent types asexemplified by the following:

(1) A resinous material largely insoluble in the oil at ordinaryatmospheric temperatures, for instance, less than 0.1% soluble at 65 or100 F. and largely soluble in the oil at elevated temperatures as, forexample, morethan 1% soluble at 200 or 300 F.

(2) A high molecular weight organic resinous material which itself maynot have the above solubility characteristics. However, in thisvariation the second phase comprises a solution of.

the resinous material in which the solvent is subimmiscible with the oileven at elevated temperatul'es or (b) immiscible with the oil atordinary temperatures (65 to 100 F.) but substantially miscible atelevated temperatures (200 to 300 F.). Where the solvent is immiscibleas in (a), it is of course essential that the oil solubility of thedissolved resinous material be such that the resinous material willremain dissolved in the solvent phase in the low temperature range butwill increase in solubility in the oil as the temperature rises, to theextent that said material will pass from the solvent phase to the oilphase.

' The resinous material may pass into and out of solution in the oil, asthe temperature varies, either by reason of variations in solubility ofthe material alone or by reason of the solvent dissolving in the oil andcarrying with it the resinous material, or because both the solvent andthe resin become more soluble in the oil.

(3) Analogous to the second variation abovedescribed, the second phasemay comprise a colloidal dispersion, i. e. an emulsion or colloidalsuspension in a "solvent or dispersing medium other than the lubricatingoil. The colloidally dispersed resinous material may thus pass fromcolloidal dispersion in the solvent to solution in the oil as thetemperature rises and then return to colloidal dispersion in thesolvent" as the temperature is again lowered.

(4) In combination with any of the above three systems, a thirdcomponent may be introduced which decreases the viscosity of the oilwhen the component is dissolved therein and which goes out ofsolution.at elevated temperature and into solution in the oil atordinary temperatures. A suitable type of third component comprises arelatively volatile material which passes out of solution at elevatedtemperatures as a vapor phase and then goes back into solution in theoil either directly as a vapor phase or after forming an intermediateliquid phase when the temperature is lowered. This type of system maytherefore involve either three or four phases, namely the lubricatingoil phase, the second liquid phase containing resinous material, thevapor phase of the third component, and a liquid phase comprising saidthird component.

This third component may advantageously be of the type which, whendissolved in the oil at low temperature, tends to force the resinousmaterial from solution in the oil into the separate second phase. Lowmolecular weight acyclic hydrocarbons, such as propane, butane, pentane,and hexane, have this additional effect on certain resinous materials.

The drawings serve to illustrate and explain the operation ofrepresentative types of systems utilizing this invention. In Figure Ithe 'first phase I, comprising lubricating oil, and the second phase 2are held in container 3 providedwith a bafile 4, inlet 5, and outlet 6.Phase 2 contains a high molecular weight organic material havingsolubility characteristics such that a substantial amount of thematerial goes into solution in the oil when the latter is at elevatedtemperatures and which goes out of solution at ordinary temperatures. Adesirable material will be less than 0.1% soluble at 65 F., more than 2%soluble at 300 F., and possess a viscosity in the order of 146,000 timesthat of the lubricating oil (viscosity being measured in centipoises).These two phases are maintained in equilibrium by the oil flowing frominlet 5 into the container around bailie 4 in contact with phase 2 t)the outlet 6. Phase 2 may comprise a high molecular weight normallyliquid resinous material or a resinous material which is either normallyliquid or normally solid, but dissolved in a. solvent as hereinabovedescribed.

Figure II shows a magnified view diagrammatically illustrating acomposition comprising the same types of components as in Figure 1.

However, in Figure II the second phase 8 is a discontinuous oneundissolved in the oil I at low temperatures, but non-colloidallydispersed therein. The discontinuous phase may be maintained indispersion by means ,of colloidal or noncolloidal peptizing agents, e.g. soaps. By "noncolloidal I mean that the dispersed particles are thanthe approximately 0.1% of the organic resinous material by weight basedon the oil will be dissolved. Substantially all of the resinous materialwill therefore be in the dispersed phase 8 and, in small proportions inthe order of 2%, it will not greatly increase the viscosity of thelubricant. The viscosity of the system may there fore approximate thenormal viscosity of the oil alone at 100 F. As the temperature of thecomposition is raised to 300 F., the dispersed phase 8 dissolves in theoil 1, increasing the viscosity thereof in an amount suflicientsubstantially to offset the decrease in viscosity of the oil, whichnormally would occur with the rise in temperature. Hence, at 300 F. allof the dispersed phase 8 may be dissolved in the oil I, and theviscosity when the level of liquid reaches a predetermined height andthereby prevents overflow. A second conduit 28 afiords means forallowing liquid l I to flow into container l3, but a check valve .21prevents flow of fluid from container l8 to container 22.

A cycle of operation of the system of-Figure III is as follows: Assumethe system to be at equilibrium at a temperature T1, e. g. at 100 atwhich temperature the solubility of phase III in the oil isnegligibleand phase l0. thereby does not substantially increase theviscosity of the oil at T1. Liquid II is substantially soluble in oil atT1, but also may appear in vapor phase l2, having a partial pressure P1.The eifect of liquid H being dimolved in the oil is to lower theviscosity of phase 9 below that which the lubricating oil alone wouldpossess at T1.

Whenthe temperature rises to T2, e. g. 200 to 300 F., the viscosity ofthe oil alone decreases greatly, but phase III comprising an organicresinous material, substantially soluble in the oil at this temperature,imparts increased viscosity to the oil by reason of its solubilitytherein, to the extent that the viscosity of the solution, even thoughstill predominantly lubricating oil, is

comparable to the viscosity of phase -9 at T1. Actually. the viscosityof the solution at T2 may be equal to or even greater than that of phase9 at T1. Further, by reason of the increase in temperature, thesolubility of component II is greatly decreased and this component-goesout of so-' of the lubricant may be equal to or even greater than thatof the lubricant at 100 F- When the temperature is lowered, the reverseeffect obtains and the resinous material precipitates out of solution inthe oil, thereby decreasing the viscosity of the lubricant to ofiset thenormal increase produced, by the lowered temperature.

Figure DI illustrates a closed lubricating system comprising an oilphase 9, a second liquid phase 10 lighter than oil and containing anorganic resinous material, a third component II which may be in liquidphase at It at low temperatures and in vapor phase I 2 the pressure ofwhich will vary with temperature. Container I3 and its appurtenances areadapted to maintain this multiphase system in substantial equilibrium.Inlet l4 and outlet l5 are provided for admitting lubricant 9 andremovingit from container l3. In the container the-oil phase iscongreater than the predetermined load on balll8 exerted by spring 20.

Container 22 is provided for holding liquid phase II and is connected tocontainer I3 by means of conduit 24 provided with valve 29, which isnormally open and allows liquid II to flow freely into and out ofcontainer l3 as the liquid is dissolved in or precipitated out of oilphase 9. A float 25 is connected to valve 29 through linkage 26 andserves to close said valve by lower temperatures.

comes more soluble in the oil, dissolves therein lution as vapor phaseat I2. In some cases the component may also form a separate liquid phaseat l8, depending upon pressures and temperatures. Release of component Hfrom solution further serves to increase the viscosity of lubricatingphase 9 and serves to enhance the action of phase I in maintaining theviscosity of phase 9 substantially constant. In some instances theremoval of component II from solution into vapor phase 12 and/or liquidphase 16 may also serve to enhance the solubility of phase I0 in phase9, thereby further magnifying the compen sating effect on viscosity.

' To complete the cycle, assume that after the system hasireachedequilibrium at T2, the temperature is again reduced-to T1. The highmolecular weight resinous material dissolved from phase II) at T2precipitates out of solution as the temperature is lowered and returnsto phase l0, thereby decreasing the viscosity of phase 9 andcompensating for the normal increase produced Component II also beas thetemperature-is lowered, and tends to reduce the viscosity of the oil.Thus, although the viscosity. of phase 9 tends to increase as thetemperature is lowered, this effect is offset by the passage of onecomponent from solution to phase I!) and passage of phases l2 and [6back into solution.

In the above description the efiectof variation of pressure in vaporphase l2 has not been discussed. At T1 phase l2 has a lower pressure P1.At T2 the pressure will be substantially greater, assuming that thevolume of phase 12 remains substantially constant. or doesnot increaseproportionally to the absolute tempera ture. Initial increase-in thepressure of phase l2 may be taken up by expansion of this gas phase toforce liquid phase l6 back into contain-.

er 22. The amount of liquid which may be forced into container 22 isdefinitely limited by float 25, which closes valve 29 at a predeterminedlevel in container 22. As the temperature continues to rise, additionalincrease of pressure may be released through valve l1 until such time asequilibrium is reached at T2. After equilibrium has been reached, thetemperature may again be reduced to T1 and pressure in phase I2 willaccordingly drop to P1.. This results in a partial vacuum and, sincevalve 29 is retained in closed position by the elevated level of fluidII in container 22, it is necessary to efiect return of component H tocontainer [3 through conduit 28. Check valve 21 in conduit 28 permitssuch return.

. Fluid ll flows through conduit 28 to container l3 until sufiicientquantity is dissolved in the oil to i reduce the level in container 22and open .valve 29, thereby allowing free communication betweencontainers 22 and I3 through conduit 24.

Figure IV illustrates a system analogous to that of Figure I, theprincipal difference being thatphase 35 comprises a colloidal dispersionof a high molecular weight organic resinous material in a continuousphase of high boiling-liquid which, like the solvent hereinabovedescribed, is immiscible with the lubricating oil at ordinarytemperatures and may or may not vary substantially in oil solubility asthe temperature rises. In this figure container 30, provided with inlet3|, outlet 32, and baflie 33, holds the lubricating oil phase 34 and thecolloidal phase 35. The dispersed material in phase 35 may be eithernormally solid, normally plastic, or normally liquid. This dispersionshould have the solubility characteristics previously described withrespect to phases 2 and 8 in Figures I and II. Thus, at

high temperatures the material dispersed in phase 35,eitherindependently or together with the dispersing medium, will becomesubstantially soluble in the oil,'dissolve therein, and maintain theviscosity within the range desired. A filter 36 is provided for removingundissolved material from the oil phase as it passes from outlet 32 to Ilubricating oil at ordinary temperatures, and

may or may not vary substantially in. oil solubility as the temperaturerises. This high boiling dispersing medium contains a high molecularweight resinous material in a colloidal state of dispersion. Thus acolloidal dispersion in a liquid medium other than the oil phase isnoncolloidally dispersed as a discontinuous phase in the continuousoilphase. The dispersion in the discontinuous phase should have thesolubility characteristics previously described with respect to phases 2and 8 in Figures I and II. At high temperatures the material dispersedin phase 39, either independently or together with the dispersing mediumof that phase, will become substantially soluble in the oil, dissolvetherein, and maintain the viscosity within the range desired.Conversely, as the temperature s lowered the dissolved material willprecipitate out of the oil into the discontinuous colloidalphase'thereby compensating for viscosity changes occurring as the oil iscooled.

The following examples and data on the viscosities of specificlubricating compositions utilizing the principles of this invention aregiven for 3 continuous phase and a rubber-like highly polymerized olefinas a discontinuous phase noncolloidally dispersed therein was prepared.The

discontinuous phase was substantially insoluble in the oil at ordinarytemperatures and therefore existed as a separate phase under suchconditions. The viscosity-temperature curves -of 1%, 2% and 5% of theolefin polymer are shown in Figure VI. Attention is particularlydirected to the following comparative viscosities of the lubricating oilper se and the two-phase lubricant:

. Viscosity in Weight per cent of polymer centlpmses a Alternativecompositions which give analogous results comprise: (l) a. lubricatingoil phase such as castor oil, other vegetable oils, or animal oils, anda second phase. of a high molecular weight iso-butene polymer; (2) aheavy linseed oil polymer of 'a jelled or semi-solid consistency,soluble at elevated temperatures such as 200-300" F. and insoluble atordinary temperatures, dispersed as a discontinuous phase in mineral oilof a suitable solvent power. In straight mineral oil, solvency andviscosity index are,relatedand it has been found that, in general, toobtain proper correlation -between the solubility of these last twophases the mineral oil should have a viscosity index above approximately50. Hydrocarbon oils prepared by polymerization of mixed butenes, withor without hydrogenation, may be substituted for the mineral oil in thiscombination.

The invention is not limited to the specific examples herein given, butcomprehends the broad combination of a plurality of phases in alubricating composition wherein the solubility characteristics of thephases are correlated as hereinbefore described. In order for thelubricant to have a substantially constant viscosity over a giventemperature range, the solubility of the resinous phase in the oil phaseshould be such that:

should approximate lflfl c k dT or, at any given temperature T withinthe range under consideration, 0 should approximate In the above, C isthe weight fraction of resinous material dissolved in the oil;

is the change in said weight fraction with change in temperature; V isthe viscosity of the lubricating oil; a is a constant of integration;and k is equal to the antilogarithm to the base e of where V1 is theviscosity of the oil and V the viscosity of the oil solution containingweight fraction C of the resin at a given temperature within the rangebeing considered.

The high molecular weight organic resinous materials having solubilitycharacteristics required for this invention may be selected fromreaction products produced by various known polymerization and/orcondensation reactions. The solubility of these reaction products may beadjusted to meet specific requirements by various expedients. Forexample, the oil solubility may be increased by introducing hydrocarbonradicals, as by alkylation of a resin-forming constituent beforepolymerization or condensation, or in some instances'by alkylatingduring or after resinification. An example of this expedient comprisesalkylation of phenol before condensation with formaldehyde to obtain aphenol formaldehyde resin. Conversely, when the reaction prodnot is toosoluble in the oil phase the solubility of this product may be decreasedto the desired valueby introducing oxygen, sulfur, nitro, amino, orother polar groups into the molecule, as by partial oxidation orsulfurization of a resinforming constituent before, during or afterresinification. An example of this procedure comprises blowing orsulfurizing a drying oil during polymerization by heating.

The following are mentioned as examples of the many types of materialsand reaction products from which the organic resinous phase may beselected and the solubility thereof correlated with the particularlubricating oil phase to obtain the results herein disclosed:polymerized styrene, hydrogenated polymerized styrene, polymerizedindene, hydrogenated polymerized di-olefins, such as hydrogenatedpolymerized butadiene or isoprene, or polymerization products ofmono-olefins, such as isobutylene, isohexane, or of terpenes,cyclohexene or tetrahydronaphthalene, polymerized esters of unsaturatedacids, preferably those in a highly polymerized state such as obtainedin the presence of a catalyst. Polymers of vinyl esters; ethers andketones may also be utilized. Resins formed by reaction of an alkyl.dihalide with an aromatic hydrocarbon, such as ethylene dichloride withbenzol, resins from alkylated phenol and formaldehyde, condensationproducts of oxygen-containing aliphatic materials of the class ofesters, ethers, acids, alcohols and ketones containing unsaturatedcarbon-tocarbon bonds such as esters of acrylic acid, as well asresinous materials formed by condensation of naphthalene, anthracene,diphenyl, with an aldehyde followed by condensation with a long chainchlorinated hydrocarbon, comprise suitable high molecular weightresinous materials from which to select a phase of the compositionherein disclosed. The above listed condensation or polymerizationproducts may be formed with the assistance of condensation andpolymerization and the like.

agents such as aluminum chloride, zinc chloride, boron fluoride and thelike.

As examples of low molecular weight fluid materials which may beutilized for reducing viscosity of the oil at low temperatures and whichwill go out of solution from the oil as a vapor phase at hightemperatures, the following are given: acetal, acetone, diethyl ketone,propyl alcohol, butyl alcohol, butyl chloride, amyl chloride, benzene,toluene, xylene, pentane, hexane, heptane, octane, cyclopentane,cyclohexane, cycloheptane, carbon disulfide, carbon tetrachloride,-chloroform, dichloroethane, and the like. Where inflammability is to, beavoided, fluids which are themselves uninflammable may be utilized ormay be mixed with normally inflammable fluids to decrease or avoidinfiammability. Such a fluid is carbon tetrachloride.

From the disclosure hereinbefore given it will be apparent that themethod of this invention comprises, broadly, contacting a lubricatingoil phase with a second phase capable of going out of and intosolution'in the oil substantially to offset viscosity changes of the oilwith alteration of temperature. More specifically, the method comprisesmaintaining a lubricating oil phase in contact with a second phasecontaining a high molecular weight resinous material, dissolving theresinous material in the oil phase as temperature rises, precipitatingthe resinous material from the oil phase to the resin phase astemperature lowers, and thereby maintaining the viscosity of thelubricating oil within predetermined limits.

By high molecular weight resinous material or high molecular weightorganic resinous material, wherever used herein, I intend'to designate anormally viscous or plastic or solid material having carbon-containingmolecules of highmolecular weight. In general, the resinous materialshould have a viscosity of at least approximately 1,000 times that ofthe lubricating oil phase and preferably a viscosity in the order of10,000 to 30,000, or more, times that of the lubricating oilphase-viscosity being measured for the purposes of this ratio incentipoises. When butene polymers are utilized as the high molecularweight material the polymer should have a molecular weight greater than2,000, and preferably in the order of 10,000.

By non-colloidal phase or macroscopic phase I mean to designate a phasewhich is present either as an independent continuous phase havingdefined boundaries or as an undissolved dispersion in which thedispersed particles are of greater than colloidal size. A macroscopicdispersion, such as utilized herein, is characterized by dispersedparticles containing at least thousands of molecules and is of a typedifferent from solutions which are characterized by dispersed particlesapproaching unimolecular size.

The lubricating oil composition of this invention may contain, inaddition to the resinous phase, compounding ingredients such as oilinessagents, extreme pressure addition agents, oxidation inhibitors, color'stabilizers, anti-sludging agents, anti-piston ring sticking agents,pour point lowering agents, dyes or blooming agents principle of thisinvention is applicable to lubricating compositions containing metalsoaps either in grease-forming proportions or in proportionsinsufiicient to form greases, .as for example in gear oils or mineralcastor machine oils.

While the character of the invention has been described in detail andnumerous examples given,

It will also be apparent that the this has been done by way ofillustration only and with the intention that no limitation should beimposed upon the invention thereby. 1 It will be apparent to thoseskilled in the art that numerous modifications and variations of theillustrative examples may be efiected in the practice of the invention,which is of the scope of the claims appeded hereto.

I claim:

1. A lubricant comprising a lubricating on phase and a high molecularweight resinous phase, said resinous phase being substantially insolublein the lubricating oil phase when cold and substantially soluble thereinwhen hot, whereby said resinous phase goes out of and into solution insaid oil phase with alteration of temperature to compensate forviscosity changes which would normally occur in said oil phase in theabsence of said resinous phase.

2. A lubricant comprising a" lubricating oil phase and a high molecularweight resinous phase, said resinous phase being substantially insolublein the lubricating oil phase at a temperature within the range ofapproximately 65 F. to 100 F. and substantially soluble therein at atemperature within the range of approximately 200 to 300 F., wherebysaid resinous phase goes out of and into solution in said oil phase withalteration of temperature to compensate for vis cosity changes whichwould normally occur in said oil phase in the absence of said resinousphase.

3. A lubricant comprising a lubricating oil phase and a high molecularweight resinous phase, said resinous phase being less than approximately0.1% soluble in the lubricatisg oil phase at a temperature within therange of approximately 65 to 100 F. and more than approximately 1%soluble therein at a temperature within the range of approximately 200to 300 F., whereby said resinous phase goes out of and into solution insaid oil phase with alteration of temperature to compensate forviscosity changes which would normally occur in said oil phase in theabsence of said resinous phase.

4. A lubricating composition as defined in claim 1, in which said highmolecular weight resinous phase comprises a discontinuous phasenon-colloidally dispersed in said lubricating oil phase.

5. A lubricating composition as defined in claim 1, in' which saidhighmolecular weight resinous phase comprises a macroscopic dispersion insaid lubricating oil phase.

6. A lubricating composition as defined in claim 1, in which said highmolecular weight resinous phase comprises a resinous material dissolvedin a high boiling solvent immiscible with the oil when cold.

7. A lubricating composition as defined in claim 1, in which said highmolecular weight resinous phase comprises a resinous material dissolvedin a high boiling solvent immiscible with the oil when cold but miscibletherewith when hot. i

8. A lubricating composition as defined in claim 1, in which said highmolecular weight resinous phase comprises a colloidal dispersion 01' aresinous material in a dispersing medium other than the lubricating oil,said dispersing medium being substantially insoluble in said lubricatingoil when cold.

9. A lubricating composition as defined in claim l. which said highmolecular weight resinous phase comprises a colloidal dispersion 01 aresinous material in a dispersing medium other than the lubricating oil,said dispersing medium being substantially insoluble in said lubricatingoil when cold but substantially soluble therein when hot.

10. A system for lubricating machine parts comprising a lubricating oilphase, a normally liquid second phase containing a resinous organicmaterial comprising long chain molecules and adapted to increase theviscosity of said lubricating oil when dissolved therein, said resinousmaterial being at least largely insoluble in said oil at approximately65 F. and at least largely soluble in said oil at approximately 300 F.,a normally fluid third phase comprising a low molecular weight fluidadapted to materially decrease the viscosity of said lubricating oilwhen dissolved therein, said fiuid being soluble in said lubricating oilat 65 F. and substantially less soluble in said lubricating oil at 300F., and means for contacting said lubricating oil with each of saidphases in at least one point in said system, whereby said resinousmaterial is dissolved in said oil and said low molecular weight fluidgoes out of solution from said oil as the temperature thereof approaches300 F., and whereby said resinous material is precipitated from solutionand said low molecular weight fluid is dissolved in said oil as thetemperature thereof approaches 65 F.

11. A method of maintaining the viscosity of a lubricating oil phasewithin predetermined limits over a temperature range of at leastapproximately F., which comprisescontacting said oil as a first phasewith a second phase containing a high molecular weight resinous materialsubstantially insoluble in said oil at the lower temperature of saidrange, dissolving the resinous material in the oil phase as thetemperature progressively rises through said range, and precipitatingthe resinous material from the oil phase as the temperature of the oilis lowered progres sively through said range.

12. A lubricant comprising a continuous lubricating oil phase selectedfrom the group consisting of animal and vegetable oils and a secondphase comprising a high molecular weight isobutene polymer substantiallyinsoluble in said continuous phase when cold and largely soluble thereinwhen .hot, whereby said second phase goes out of and into solution insaid oil phase with alteration of temperature to compensate forviscosity changes which would normally occur in said oil phase in theabsence of said second phase.

13. A lubricant comprising a continuous lubricating oil phase of castoroil and a second phase comprising a high molecular weight isobutenepolymer substantially insoluble in said continuous phase when cold andlargely soluble therein when hot, whereby said second phase goes out orand into solution in said oil phase with alteration of temperature tocompensate for viscosiw changes which would normally occur in said oilphase in the absence of said second phase.

14. A lubricant comprisinga continuous lubricating oil phase of lard oiland a second phase comprising a high molecular wei'ght isobutene polymersubstantially insoluble in said continuous phase when cold and largelysoluble therein when hot, whereby said second phase goes out of and intosolution in said oil phase with alteration of temperature to compensatefor viscosity changes which would normally occur in said oil phase inthe absence of said second phase.

16. A lubricant comprising a continuous hy- 15. A lubricant comprising acontinuous hy drocarbon lubricating oil phase and a second phasecomprising a heavy linseed oil polymer of a gelled or semi-solidconsistency, said polymer being soluble in said hydrocarbon oil atelevated temperatures of from approximately 200 to 300 F. and insolubletherein at ordinary atmospheric temperatures, said lubricating oil phasehaving in the absence of the second phase a viscosity index aboveapproximately 50, whereby said polymer goes out of and into solution insaid oil phase with alteration of temperature to compensate forviscosity changes which would normally occur in said ofl phase in theabsence of said second phase.

by said second phase goes out of and into solution in said oil phasewith alteration of temperature to compensate for viscosity changes whichwould normally occur in said oil phase in the absence of'said secondphase.

' AUGUSTUS H. BATCHELDER;

